Fluid injection apparatus with improved contrast visualization

ABSTRACT

An apparatus and method for manually injecting fluid into a patient with improved contrast visualization are disclosed. The apparatus includes a syringe having a cylinder in which a plunger is reciprocatingly mounted. The syringe is connected to a manifold which itself is connected to a source of radiopaque contrast. Retraction of the plunger within the cylinder draws contrast into the cylinder, and depression of the plunger forces the contrast through the manifold and into a patient through a catheter. In order to increase the speed of injection and thus the visualization of the contrast, an improved visualization device is provided which may be provided in the form of a heater or, alternatively, in the form of an expandible catheter. The heater may be positioned anywhere within the apparatus to elevate the temperature of the contrast material, which in turn reduces its viscosity and thereby increases the speed with which fluid may be injected. The expandible catheter, may be used to restrict blood flow through a vascular structure so that the contrast material may be injected into the patient with lessened resistance and dilution from blood flow.

FIELD OF THE INVENTION

[0001] The invention generally relates to fluid injection apparatus and,more particularly, relates to manually operated syringes.

BACKGROUND OF THE INVENTION

[0002] Many medical procedures require the injection of fluid. Oneexample is angiography. Angiography is a procedure used in the detectionand treatment of abnormalities or restrictions in blood vessels. Duringangiography, a radiographic image of a vascular structure is obtained byinjecting radiopaque fluid or contrast through a catheter into a vein orartery. Vascular structure fluidically connected with the vein or arteryin which the injection occurs is filled with the contrast material.X-rays are then passed through the region of the body in which thecontrast material was injected, with the x-rays being absorbed by thecontrast material, creating a radiographic outline or image of the bloodvessel containing the contrast material. The x-ray image of the bloodvessels filled with the contrast material is usually recorded onto filmor videotape and then displayed on a fluoroscope monitor.

[0003] The speed with which the injection of contrast occurs enhancesthe resulting radiographic image because the speed of injectioncounteracts the flow of blood through the vessels that continuallycarries or flushes the contrast away. The faster the injection ofcontrast means a higher concentration of the contrast during the x-rayimaging and therefore a higher radiopacity of the blood vessels. Due tothe high viscosity of the contrast material, and the flow resistance inthe catheter and other fluid channels, the force required for rapidinjection of a contrast is relatively high.

[0004] An additional factor contributing to the high forces required forplunger depression is that as current technology has evolved, thecatheters used for angiography have reduced in size. The outletdiameters of the catheters have been reduced to four or five French sizecatheters. As a result, the force required to inject into the arterieshas increased significantly.

[0005] Currently, manual syringes are used to inject contrast into mostarteries. When large flow rates of contrast are required, as is the casefor ventrilography (injecting into the left ventricle), a power injectoris typically used because manual syringes cannot be operated withsufficiently high flow rate due to the inability to apply enough manualforce on the syringe plunger. The power injector is operated by firstsetting a flow rate and an injection volume. The operator then activatesthe system by pressing a button on a hand controller which actuates amotor or the like for injecting the contrast. Examples of such powerinjectors are disclosed in U.S. Pat. Nos. 5,515,851 and 5,916,165.

[0006] However, while such power injectors are preferable in certainapplications, in other instances, it would be advantageous to use amanual syringe. One advantage of using a manual syringe is that theoperator is provided with more direct control of the injection. Forexample, if resistance is encountered during the injection process, theoperator can detect the resistance due to an increase in the pressure,and thus the force required to manually depress the plunger.

[0007] It would therefore be advantageous to provide a fluid injectionapparatus which enables the injection to be performed manually, butwhich reduces the force required for such manual operation withoutemploying a power injector.

SUMMARY OF THE INVENTION

[0008] In accordance with one aspect of the invention, a fluid injectionapparatus adapted to inject fluid is provided which comprises an inputdevice, a catheter, and an improved visualization device. The catheteris in fluid communication with the input device. The improvedvisualization device is adapted to increase the speed with which fluidmay be injected.

[0009] In accordance with another aspect of the invention, a method ofmanually injecting fluid is provided which comprises the steps ofretracting a plunger from a syringe cylinder and drawing fluid into thecylinder, depressing the plunger into the cylinder forcing the fluid outan outlet of the cylinder, increasing the speed with which fluid may beinjected, and injecting the fluid into a patient.

[0010] In accordance with another aspect of the invention, a manuallyoperated fluid injection apparatus is provided which comprises asyringe, a manifold, a fluid line, a catheter, a source of fluid, and aheater. The syringe includes a movable plunger, while the manifoldincludes a plurality of inlet ports in first and second ends. Thesyringe is connected to the first end of the manifold. The catheter isconnected to the second end of the manifold. The source of fluid is incommunication with one of the manifold inlet ports via the fluid line,while the heater is operatively associated with one of the syringe,manifold, fluid line, catheter, or source of fluid.

[0011] In accordance with another aspect of the invention, a manuallyoperated fluid injection apparatus is provided which comprises asyringe, a manifold, a fluid line, a catheter, a source of fluid, and anexpandable ring. The syringe includes a movable plunger, while themanifold includes a plurality of inlet ports in first and second ends.The syringe is connected to the first end of the manifold. The catheteris connected to the second end of the manifold. The source of fluid isin communication with one of the manifold inlet ports via the fluidline, while the expandable ring is associated with the catheter and isexpandable after catheter insertion and prior to injection to constrictblood flow.

[0012] In accordance with another aspect of the invention a manuallyoperated fluid injection system is provided which comprises amanipulable input device, and a heater associated with the input deviceand adapted to increase the temperature of fluid prior to injection.

[0013] In accordance with another aspect of the invention a manuallyoperated fluid injection system is provided which comprises amanipulable input device, a catheter connected to the input device, andan expandable member associated with the catheter and adapted to expandafter the catheter is inserted into a patient to restrict blood flowduring injection.

[0014] These and other aspects and features of the invention will becomemore apparent from the following detailed description when taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a schematic representation of a manual fluid injectionapparatus constructed in accordance with the teachings of the invention;

[0016]FIG. 2 is a block diagram of an alternative embodiment of a fluidinjection apparatus constructed in accordance with the teachings of theinvention; and

[0017]FIG. 3 is a flow chart of a sample sequence of steps which may betaken by a fluid injection system constructed in accordance with theteachings of the invention.

[0018] While the invention is susceptible to various modifications andalternative constructions, certain illustrative embodiments thereof havebeen shown in the drawings and will be described below in detail. Itshould be understood, however, that there is no intention to limit theinvention to the specific forms disclosed, but on the contrary, theintention is to cover all modifications, alternative constructions andequivalents falling within the spirit and scope of the invention asdefined by the appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Referring now to the drawings, and with specific reference toFIG. 1, a manually operated fluid injection apparatus constructed inaccordance with the teachings of the invention is generally depicted byreference numeral 20. The apparatus 20 is depicted in reference to amanually operated apparatus 20 for the injection of radiopaque contrastfrom a supply 22 to a patient (not shown). However, it is to beunderstood that the teachings of the invention can be used for theinjection of other fluids as well, and in power-assisted, or automaticinjection systems as well.

[0020] As shown in FIG. 1, the apparatus 20 includes a manually operatedsyringe 24, a manifold 26, a first fluid line 28, a second fluid line30, a catheter 32, and an improved visualization device 34.

[0021] The syringe 24 includes a cylinder 36 in which a plunger 38 isdisposed for translational movement. The plunger 38 includes a thumbring 40, as well as a rubber or otherwise elastomeric stopper 42engaging an inner circumferential surface 44 of the cylinder 36. Firstand second finger rings 46 and 48 extend from the cylinder 36 tofacilitate operation of the syringe 24 in conjunction with the thumbring 40. The cylinder 36 includes a reduced diameter outlet 50 connectedto a first end 52 of the manifold 26. A threaded or other suitablecoupling 54 is provided for attachment therebetween.

[0022] The manifold 26 includes the first end 52, a second end 56, and aplurality of valved inlet ports 58 a, b, and c. As shown in FIG. 1,inlet port 58 c is connected to the first fluid line 28 for receipt ofcontrast from the supply 22. The second inlet port 58 b, is connected toa source of saline 60 by way of the second fluid line 30. The thirdinlet port 58 a, is shown connected to a pressure transducer 64. Thesecond end 56 of the manifold 26 is connected to the catheter 32.

[0023] The first fluid line 28, connecting the source of contrast 22 tothe manifold 26, may include a valve 66 as well as a vent 68. The valve66, which may be provided in the form of a stop cock, is provided tocontrol flow of contrast from the source of contrast 22 to the manifold26. The vent 68, is provided to aerate any air or gas within the firstfluid line 28.

[0024] The catheter 32 includes a proximal end 70, and a distal end 72.As shown in FIG. 2, in an alternative embodiment the distal end 72 ofthe catheter 32 may be provided with an expandable ring 74, theimportance of which will be discussed in further detail herein. Theexpandable ring 74 may be provided in the form of an elastomeric hollowring which upon introduction of compressed air or the like, may expandto increase the diameter of the catheter 32.

[0025] Referring again to FIG. 1, the improved visualization device 34is shown proximate the catheter 32. The improved visualization device 34may be provided in the form of a heater, or may include the expandablering 74. The heater 76 can be provided in a variety of radiant,convective and conductive forms, including conventional heating coilswhich, upon electrical actuation, elevate temperature to therebyincrease the temperature of the catheter 32 and thus the temperature ofthe contrast within the catheter 32. Alternatively, the heater 76 may beprovided in the form of conduits or tubes wrapped around the catheter 32or other parts of the apparatus 20 and through which a relatively warmfluid is passed for heating of the contrast. In a still furtheralternative, the heater 76 may be embedded directly in the apparatus 20.More specifically, resistor coils or other heating devices may beprovided in the body of the syringe 24, the manifold 26, the first fluidline 28, the second fluid line 30, or the catheter 32. However, theinventor has found that it is beneficial to provide the heater 76 asclose to the end of the catheter 32 inserted into the patient aspossible to lessen the cooling effects of traveling through theapparatus 20.

[0026] The improved visualization devices 34 are provided to increasethe speed with which the contrast may be injected to thereby minimizethe effect of blood flow washing the contrast away and lessening thevisual radiographic image generated. In the embodiment employing theheater 76, the speed is increased by elevating the temperature of thecontrast, which in turn decreases its density and decreases itsviscosity. Accordingly, the contrast is more easily injected. In theembodiment employing expandable ring 74, the size of the catheter 32 isincreased after placement within the vascular structure of the patient.In so doing, blood flow is restricted through the vascular structure,momentarily, while the contrast is injected. The contrast therefore isinjected with less mixing with blood flow and less dilution of thecontrast. After injection of the contrast, the expandable ring can bedeflated and the catheter 32 can be removed thereby allowing blood flowto return to normal. The heater 76 and the expandable ring 74 may becombined in the same system or apparatus 20.

[0027] In operation, the apparatus 20 may be used to inject fluid into apatient with increased speed. As shown in FIG. 3, which is a sampledepiction of steps which may be taken by the apparatus 20, after thevalve 66 is opened, the process is initiated by opening the valved port58 c, as indicated by step 78. In so doing, fluid flow is communicatedfrom the source of contrast 22, through the manifold 26 and to theoutlet 50 of the syringe 24. The contrast 22 is able to enter thecylinder 36 of the syringe 24 upon retraction of the plunger 38, asindicated by step 80. More specifically, the retraction of the plunger38 within the cylinder 36 creates a vacuum within the cylinder 36,thereby drawing the contrast into the syringe 24. The plunger 38 may beretracted a distance sufficient to fill the cylinder 36 to theappropriate volume. A series of indicia or graduations may be providedon the side of the cylinder to facilitate such operation.

[0028] Once the syringe 24 is filled to the appropriate volume, theplunger 38 is reciprocated back into the cylinder 36 as indicated bystep 82. In so doing, the contrast 22 is forced from the cylinder 36into the manifold 26, through the catheter 32, and into the patient.While passing through the components of the apparatus 20, the contrastfluid 22 is heated, as indicated by step 84. In so doing, the densityand viscosity of the contrast 22 are decreased, and the force requiredby the user to depress the plunger 38 is decreased, and the speed ofinjection is increased.

[0029] In an optional step 86, the catheter 32 may be expanded inconjunction with the heating step 84. In so doing, the catheter 32restricts blood flow through the vascular structure in which thecatheter 32 is placed. The contrast 22 can therefore be injected intothe patient in step 88 with lessened interference and dilution fromblood flow. Once the contrast 22 is fully injected, the catheter can bedeflated and removed. It is to understood that the expansion of thecatheter step 86 may be conducted in the absence of the heating step 84,and similarly, that the heating of the contrast 84 can be conducted inthe absence of the catheter expansion step 86.

[0030] From the foregoing, it can be seen by one of ordinary skill inthe art that the teachings of the invention may be utilized to provide amanual fluid injection apparatus and method which reduces the forcerequired by an operator to manually inject fluid into a patient,increases the speed of injection, and improves the contrastvisualization on the resulting radiographic image.

What is claimed is:
 1. A fluid injection apparatus adapted to injectfluid, comprising: an input device; a catheter in fluid communicationwith the input device; and an improved visualization device operativelyassociated with one of the input device and catheter and adapted toincrease the speed with which fluid may be injected.
 2. The fluidinjection apparatus of claim 1, wherein the input device is a syringe.3. The fluid injection apparatus of claim 2, wherein the syringe ismanually operated.
 4. The fluid injection apparatus of claim 1, whereinthe improved visualization device is a heater adapted to increase thetemperature of the fluid.
 5. The fluid injection apparatus of claim 1,wherein the improved visualization device is an expandable memberproximate a distal end of the catheter.
 6. The fluid injection apparatusof claim 1, further including a manifold and a fluid line, the manifoldhaving first and second ends and a plurality of input ports, the syringebeing connected to the first end of the manifold, the fluid line beingconnected to one of the input ports of the manifold.
 7. The fluidinjection apparatus of claim 6, wherein the catheter is connected to thesecond end of the manifold.
 8. The fluid injection apparatus of claim 7,wherein the fluid is radiopaque contrast.
 9. The fluid injectionapparatus of claim 7, wherein the fluid line includes a valve.
 10. Thefluid injection apparatus of claim 4, wherein the heater is positionedproximate the catheter.
 11. The fluid injection apparatus of claim 4,wherein the heater is an electric heating coil.
 12. The manuallyoperated fluid injection apparatus of claim 4, wherein the heateremploys a form of heating selected from the group of heating formsincluding radiant, convective, and conductive.
 13. The fluid injectionapparatus of claim 4, wherein the heater is integrated into one of thesyringe, fluid line, manifold, and catheter.
 14. A method of manuallyinjecting fluid, comprising the steps of: retracting a plunger from asyringe cylinder and drawing fluid into the cylinder; depressing theplunger into the cylinder forcing the fluid out of an outlet of thecylinder; increasing the speed with which the fluid may be injected; andinjecting the fluid into a patient.
 15. The method of manually injectingfluid of claim 14, wherein the increasing step includes the step ofreducing the viscosity of the fluid.
 16. The method of manuallyinjecting fluid of claim 15, wherein the viscosity of the fluid isreduced by heating the fluid.
 17. The method of manually injecting fluidof claim 16, wherein the fluid is injected into the patient with acatheter, and wherein the heating step occurs proximate the catheter.18. The method of manually injecting fluid of claim 14, wherein theincreasing step is performed by constricting blood flow proximate anarea of injection.
 19. The method of manually injecting fluid of claim18, wherein the fluid is injected with a catheter, and wherein the bloodflow is constricted by enlarging the size of the catheter.
 20. Amanually operated fluid injection system, comprising: a syringe having amovable plunger; a manifold having a plurality of input ports and firstand second ends, the syringe being connected to the first end of themanifold; a fluid line having first and second ends, the first end ofthe fluid line being connected to one of the plurality of input ports; acatheter connected to the second end of the catheter; a source of fluidin communication with the fluid line; and a heater operativelyassociated with one of the syringe, manifold, fluid line, catheter andsource of fluid.
 21. The manually operated fluid injection system ofclaim 20, wherein the fluid is radiopaque contrast.
 22. The manuallyoperated fluid injection system of claim 20, wherein a valve isinterposed in the fluid line for controlling fluid flow therethrough.23. The manually operated fluid injection system of claim 20, whereinthe heater is integrated with one of the syringe, manifold, fluid line,and catheter.
 24. A manually operated fluid injection system,comprising: a syringe having a movable plunger; a manifold having aplurality of input ports and first and second ends, the syringe beingconnected to the first end of the manifold; a fluid line having firstand second ends, the first end of the fluid line being connected to oneof the plurality of input ports; a catheter connected to the second endof the catheter; a source of fluid in communication with the fluid line;and an expandable ring associated with the catheter, the ring beingexpandable after catheter insertion and prior to injection to constrictblood flow.
 25. The manually operated fluid injection system of claim24, wherein the fluid is radiopaque contrast.
 26. The manually operatedfluid injection system of claim 24, wherein a valve is interposed in thefluid line for controlling fluid flow therethrough.
 27. A manuallyoperated fluid injection system, comprising: a manipulable input device;and a heater associated with the input device and adapted to increasethe temperature of fluid prior to injection.
 28. The manually operatedfluid injection system of claim 27, wherein the fluid is radiopaquecontrast.
 29. The manually operated fluid injection system of claim 27,wherein the heater is integrated into the input device.
 30. The manuallyoperated fluid injection system of claim 27, wherein the heater is anelectric coil.
 31. The manually operated fluid injection system of claim27, wherein the heater employs a form of heating selected from the groupof heating forms including radiant, convective and conductive.
 32. Amanually operated fluid injection system, comprising: a manipulableinput device; a catheter connected to the input device; an expandablemember associated with the catheter and adapted to expand after thecatheter is inserted into a patient to restrict blood flow duringinjection.